Improved Theoretical Ground-State Energy of the Hydrogen Molecule

Abstract

The potential‐energy curve for the electronic ground state of the hydrogen molecule has been calculated for 1 ≤ R ≤ 3.2 a.u. in double precision and using a 100‐term expansion for the electronic wavefunction. Accuracy of the previously computed diagonal corrections for nuclear motion has been tested. The vibrational equation has been solved for all isotopes of the hydrogen molecule and for the rotational quantum number $\text{J\hspace{0.17em}≤\hspace{0.17em}10}$ . The calculated adiabatic dissociation energy of H₂, corrected for relativistic and radiative effects, is by 3.8 cm⁻¹ larger than the experimental value, hence the theoretical total energy is by the same amount lower than the experimental value. The calculated vibrational quanta for H₂ are by 0.5–0.9 cm⁻¹ larger than the experimental ones.